diff options
| author | Kevin Wolf <kwolf@redhat.com> | 2014-05-08 13:35:09 +0200 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2014-05-19 11:36:49 +0200 |
| commit | d66e5cee002c471b78139228a4e7012736b375f9 (patch) | |
| tree | e6304da0d058cf822920f6e833695eaf6ca7f189 | |
| parent | 46485de0cb357b57373e1ca895adedf1f3ed46ec (diff) | |
qcow1: Stricter backing file length check
Like qcow2 since commit 6d33e8e7, error out on invalid lengths instead
of silently truncating them to 1023.
Also don't rely on bdrv_pread() catching integer overflows that make len
negative, but use unsigned variables in the first place.
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
| -rw-r--r-- | block/qcow.c | 7 | ||||
| -rwxr-xr-x | tests/qemu-iotests/092 | 11 | ||||
| -rw-r--r-- | tests/qemu-iotests/092.out | 7 |
3 files changed, 23 insertions, 2 deletions
diff --git a/block/qcow.c b/block/qcow.c index 3566c05b0f..7fd57d744a 100644 --- a/block/qcow.c +++ b/block/qcow.c @@ -97,7 +97,8 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags, Error **errp) { BDRVQcowState *s = bs->opaque; - int len, i, shift, ret; + unsigned int len, i, shift; + int ret; QCowHeader header; ret = bdrv_pread(bs->file, 0, &header, sizeof(header)); @@ -202,7 +203,9 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags, if (header.backing_file_offset != 0) { len = header.backing_file_size; if (len > 1023) { - len = 1023; + error_setg(errp, "Backing file name too long"); + ret = -EINVAL; + goto fail; } ret = bdrv_pread(bs->file, header.backing_file_offset, bs->backing_file, len); diff --git a/tests/qemu-iotests/092 b/tests/qemu-iotests/092 index ae6ca763a0..a8c0c9ca2b 100755 --- a/tests/qemu-iotests/092 +++ b/tests/qemu-iotests/092 @@ -43,6 +43,8 @@ _supported_fmt qcow _supported_proto generic _supported_os Linux +offset_backing_file_offset=8 +offset_backing_file_size=16 offset_size=24 offset_cluster_bits=32 offset_l2_bits=33 @@ -81,6 +83,15 @@ poke_file "$TEST_IMG" "$offset_size" "\xee\xee\xee\xee\xee\xee\xee\xee" poke_file "$TEST_IMG" "$offset_size" "\x7f\xff\xff\xff\xff\xff\xff\xff" { $QEMU_IO -c "write 0 64M" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir +echo +echo "== Invalid backing file length ==" +_make_test_img 64M +poke_file "$TEST_IMG" "$offset_backing_file_offset" "\x00\x00\x00\xff" +poke_file "$TEST_IMG" "$offset_backing_file_size" "\xff\xff\xff\xff" +{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir +poke_file "$TEST_IMG" "$offset_backing_file_size" "\x7f\xff\xff\xff" +{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir + # success, all done echo "*** done" rm -f $seq.full diff --git a/tests/qemu-iotests/092.out b/tests/qemu-iotests/092.out index ac03302d86..496d8f0a63 100644 --- a/tests/qemu-iotests/092.out +++ b/tests/qemu-iotests/092.out @@ -28,4 +28,11 @@ qemu-io: can't open device TEST_DIR/t.qcow: Image too large no file open, try 'help open' qemu-io: can't open device TEST_DIR/t.qcow: Image too large no file open, try 'help open' + +== Invalid backing file length == +Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 +qemu-io: can't open device TEST_DIR/t.qcow: Backing file name too long +no file open, try 'help open' +qemu-io: can't open device TEST_DIR/t.qcow: Backing file name too long +no file open, try 'help open' *** done |